So that’s why beleaguered Office Depot‘s (NYSE:ODP) stock is up 40% in the last week and about 73% in just September alone: Activist fund Starboard Value disclosed Monday it has built a 13.3% stake in the struggling retailer and intends to hold management’s feet to the fire.

Moreover, the awful economy both here and abroad — and massive losses of government jobs at the local, state and federal level — have made the business of big-box office supply retailers tougher than ever.

That has shares reeling — and left them vulnerable to activist investors like Starboard and perhaps private equity firms, too. Staples has gotten a recent bump from rumors that Bain Capital is kicking the tires on a take-out, notes InvestorPlace assistant editor Marc Bastow.

And just like that, the big-box office retailers are in play.

Hey, that’s great if you’re a professional trader — and perhaps of solace to any long-suffering shareholder looking to exit at a profit.

But for long-term value investors, all this Wall Street heat and light is largely immaterial. The macro and company-specific fundamentals haven’t changed a whit.

There’s a huge difference between trading and investing: If you don’t own Office Depot, Staples or OfficeMax, don’t start now.

As of this writing, Dan Burrows did not hold a position in any of the aforementioned securities.